1. Field of the Invention
The present invention relates to a technology for determining whether to authorize a service transfer based on reliability of a partner device or a partner user when a user of one device authenticates a user of other device to exchange the service between devices connected to a network.
2. Description of the Related Art
Conventionally, for using a service provided on the Internet, generally a user logs on to the service by using a combination of a user identification (ID) and a password etc. In other words, for logging on to the service and receiving the provided service, the user must undergo user authentication by an authenticating system that is mounted on a server that provides the service. The user can use the service only after the user is authenticated as an authorized user via the user authentication.
Generally, the service is provided after confirming the safety of service use authority and a communication path that are possessed by the user who is authenticated by the authentication system. Thus, a service provider selects the user via an authentication process that confirms authenticity of the user and an authorization process that confirms safety of the use authority and the communication path of the user, and provides the appropriate data to the selected user.
For example, in a service selecting and providing method disclosed in Japanese Patent Application Laid-Open No 2002-300191, a service is selected and provided according to terminal attributes of the user in response to a service provision request from the user to a service providing device. If the service provision request is a request for fetching an electronic mail and the terminal includes a communication line having a communication speed with high terminal attributes, a service is selected and provided that causes the terminal to fetch an electronic mail that includes an attached file having a large file size. If the terminal includes a communication line having a communication speed with low terminal attributes, a service is selected and provided that causes the terminal to fetch an electronic mail that does not include an attached file having a large file size.
In a service providing system disclosed in Japanese Patent Application Laid-Open No 2003-216582, based on a security level according to a relation between user attributes and provided services, a service from a plurality of services is selectively provided to the user. Further, the aforementioned service providing system enables to carry out update of the security level according to system operation status, thereby enabling to enhance both operability and security.
However, in the conventional technology represented in Japanese Patent Laid-Open Publication No 2002-300191 and Japanese Patent Laid-Open Publication No 2003-216582, because only the service provider unilaterally determines the user's attributes and selects the service that is provided, the user does not have any option. In other words, in the authorization process, the user does not have an option that enables the user to safely receive the provided service after learning attributes related to reliability such as safety of the service provider, communication performance etc.
In general, the service provider also prefers to provide a service while excluding a potentially intimidating user. However, in the conventional technology represented in Japanese Patent Laid-Open Publication No 2002-300191 and Japanese Patent Laid-Open Publication No 2003-216582, the authorizing process does not explicitly provide a criterion that would enable the service provider to identify a potentially intimidating user, and the service provider has to provide the service assuming that the user is trustworthy.
Because the conventional technology is based on the assumption that the user is trustworthy to some extent only via the authentication process, the authorization process does not enable the service provider to select the user, and conversely, does not enable the user to select the service. For this reason, recently provision and use of various services on the Internet is also accompanied by a steep rise in fraudulent acts such as impersonation and unauthorized access.